[sumo911]

I had this experience on both the T-mobile stock ROM as well as a few custom ROMs from here and XDA. What I did to improve the music tab experience was reformat my sdcard and set up my library (folder structure) as such:

Storage card > Music > Artist > Album > and then inside this folder would the the mp3 files associated with that particular artist....and so on. This dramatically helped the loading of files and cover images in Manila's music tab. Whereas before, I had all my music files inside one folder and it would take up to a minute for the music tab to load the 4+GB of music on have on my card.